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0. M. GRACE;

BLOCK SIGNAL TELEGRAPH.

N0. 556,670. Patented Mar. 17, 1896.

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UNITED STATES PATENT Erica CLAUDE M. GRACE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE- IIALF TO ARTHUR E. BRAGG, OF SAD/[E PLACE.

BLOCK-SIGNAL TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 556,670, dated March 1'7, 1896. Application filedSeptember 10, 1895. Serial No. 562,067 No modelfi To all whom it may concern:

Be it known that I, CL: UDE M. GRACE, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Block-Signal Telegraphs, of which the following is a specification.

My invention relates to a new and useful improvement in signal-telegraphs for railway block systems, and has for its object to pro vide a system of telegraphy which may be operated by a dynamo-current proceeding from a single generator, each station being adapted to draw current from a common feed-wire and signal on either or both sides of a linewire.

With these ends in view my invention consists in the details of construction and combination of elements hereinafter set forth, and then specifically design ated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same, I will describe its construction and operation in detail, referring by number to the accompanyin g drawings, forming a part of this specification.

Figure 1 is a'diagrani of a station and its connection with the feed-wire and line-wi res. Fig. 2 is a side elevation of a single-pointed key which is used to signal by this system. Fig. 3 represents one of the two-pointed keys which I use.

Referring to the drawings, 1 represents a dynamo; 2, the feed-wire leading therefrom and upon which it is preferable to maintain about one hundred and ten volts.

- 3 and a are the line-wires which pass into and out of the station 5, which in the case of a railway block system represents one of the towers thereof.

6 is a branch of the feed-wire, which, passing through a lamp 7 or other resistance whereby the voltage of the feed-wire is reduced, enters the station at a binding-post S, and from this post a short wire 9 leads to the post 10, from whence two wires 11 and 12 run in opposite directions and terminate in the posts 13 and 11.

is a two-pointed key having its base connected through wire 17 to sounder 19, which is connected to section 3 of the line-wire, its nearer point connected to post 13 through wire 28 and its farther point connected to wire 21. 1G is a similar key having like connection to sounder 20, which is connected to section-t of the feed-wire, wire 21 and post 14: by wires and 18. These keys 15 and 16 are held normally closed on the farther points by springs, but break connection with the farther points and make connection with the nearer points when the keys are depressed.

is a two-point switch having its base connected to the wire 21 by the branch wire 22 and having one point grounded by wire 21 and the other point 30 connected to the base of a single-pointed key 27 through wire and post 26, said key being normally open and having its contact-point connected to wire 12 by wire The ground-switch is normally closed on the point and only changed to ground when a message is to be sent or received on one side of the line only.

It will be understood that each of the towers or stations 5 within this system is provided with similarlywired instruments as that just described, and it will therefore be seen that each station may by the proper manipulation of its instruments draw the needed energy from the feed-wire to signal the remainin g stations of the system.

A signal entering a tower in the direction of the arrow a will pass through the sounder 19 and closed point of the key 15, along the wire 21, through the closed point of the key 16, along the wire 18 and through the sounder. 20 and to line by the section 4, and as the keys 15 and 16 are normally closed upon the side of the wire 21 it follows that a signal may pass through each of the towers without care or attention from the operator within unless the switch 23 is grounded, when the current will be intercepted by the wire 22 and carried to ground by switch 23 and wire 21.

To send a signal over the section 3 of the line-wire without affecting section &, first the switch 23 is grounded, then the key 15 is manipulated, whereby energy is taken from the branch 6 over the wire 11 and put to line through the sounder 19, and said signal is prevented from being grounded through wire 22, &c., by the key 15 breaking contact with its farther point, and a like effect will be had in sending a signal over section 4 by the manipulation of the key 16, the energy for said signal being drawn over the wire 12; but should it be desired to signal in both directions upon the line-wire the lever of the switch 23 is changed from ground to termination of the wire 25 and the two-point key27 manipulated, in which case energy is drawn from the wire 12 and the signals transmitted along the wire 25, through the switch-lever 23, then in the position shown in dotted lines along the wire 22 to the Wire 21, by which it is divided and passed over the wires 17 and 18, through the sounders 19 and 20 and to line over the sections 3 and l, as will be readily understood.

Since the keys 15 and 16 are closed next the line-wire and open next the feed-wire terminals and the key 27 is open, no current is permitted to pass to line until one or another of the keys is operated, and this maintains a clear line-wire over which signals may pass to and fro without interruption or liability of disarrangcment bythc carelessness of an operator.

By the use of the two sounders, one upon either side of the keys, a message maybe received from either direction, or permitted to pass through the tower to the next station, by the proper arrangement of the groundswitch.

The feed-wire 2 may receive its supply of current from the same source as the ordinary telegraph system along the railway, thus renderin g unnecessary the establishing of a separate generating-station, at the same time giving each station perfect control of its electrical energy without the use of batteries.

In practice this system is quicker, cheaper, more economical and reliable than any other system now in use for reporting trains between towers for the purpose of preventing accidents to trains.

Having thus fully described my invention. what I claim as new and useful is 1. A telegraph system, consisting of a suitably-charged feed-wire, a number of stations connected in multiple to said feed wire through suitable resistances, each station provided with a loop of a line-wire, two sounders, one on each side of the loop, two two-pointed keys normally completing the loop through a bridge-wire, a switch having its arm connected with the bridge-wire and one of its points grounded, a single-pointed normally-open key connected to another point of the switch and conductors connecting the normally-open contact-points of the three keys to the feed-wire as and for the purpose described.

2. In a telegraph system consisting of a suitably-charged feed-wire, a line-wire, a number of stations connected in multiple through suitable resistance to said feed-wire. each station provided with a loop of the linewire, two sounders, one on each side of the loop, two two-pointed keys, normally completing the loop through a bridge-wire, a switch having its arm connected with the bridge-wire and its contact-point grounded and a conductor connecting the normallyopen contact-points of the keys to the feedwire, as and for the purpose described.

A telegraph system consisting of a feed- Wire, a line-wire, a number of stations connected to the feed-Wire and line-wire, each station provided with two sounders in the line-wire, means for grounding the line-wire between the sounders and means in the linewire for breaking connection with the ground and making connection with the feed-wire on either side of the ground connection, as and for the purpose described.

In testimony whereof I have hereunto affixed my signature in the presence of two subscribing witnesses.

CLAUDE M. GRACE.

\Vitncsses:

S. S. WILLIAMsoN, SAMUEL L. TAYLOR. 

